A proposal to compensate platform attitude deviation's impact on laser point cloud from airborne lidar

The attitude deviations of an airborne stabilized platform have significant impact on the distribution and point density of the laser point cloud obtained from airborne LiDAR. On one hand, the attitude deviations can cause the laser point cloud to horizontally shift along the scanning direction, leading to the coverage area deviating from the target terrain and resulting in missing scan of some important topography. On the other hand, the attitude deviations can cause the point density to be nonuniform, further deteriorating the elevation accuracy of the digital surface model (DSM) reconstructed from the laser point cloud. Among the three attitude deviations of the airborne stabilized platform, the roll and pitch deviations have more significant impact than the heading deviation. Thus, it is of practical importance to take appropriate steps to compensate the attitude deviations of the airborne stabilized platform, especially for the roll and pitch deviations. In this paper, firstly, an attitude compensation device was designed to compensate the impact of both the roll and pitch deviations in real time. Then, through numerical simulation and semi-physical simulation experiments, the compensation effectiveness of the device was evaluated. The experimental results show that the device can effectively compensate the roll and pitch deviations. After the compensation of the roll and pitch deviations, offsets of the distribution of the laser point cloud were well corrected, and the elevation accuracy of the reconstructed DSM was improved.